1. Field of the Invention
The present invention relates to a lifting structure for an input device, especially to a lifting structure for a touchpad.
2. Description of the Prior Arts
Touchpad is a common input device in electronic devices nowadays, and is especially common in portable electronic devices, such as laptop. The touchpad can replace a mouse and enable a user to control the portable electronic device to move a cursor on a screen without using the mouse.
The conventional touchpad has to be operated with two keys. The keys are disposed underneath the touchpad, and the two keys each respectively correspond in function to a left button and a right button of the mouse. For operating the touchpad and the keys, the user moves the cursor on the touchpad and clicks on the keys.
However, the touchpad nowadays can do without the keys and is pressable. The touchpad has to be operated with a switch disposed beneath the touchpad. When the touchpad is pressed down, the touchpad abuts and actuates the switch. Meanwhile, the touchpad detects that the user presses a right part or a left part of the touchpad, so as to identify whether the user intends to achieve the function of clicking the left button or the right button.
With reference to FIGS. 14 and 15, the user may press on any location on the touchpad 91, but the touchpad 91 should always be moved down evenly without tilting. Thus, there is a scissor mechanism mounted between the touchpad 91 and a base 92 disposed beneath the touchpad 91. The scissor mechanism has two frames 93. Each frame 93 is looped into a rectangle, and has a bottom segment 931, a side segment 932 and a top segment 933 connected to one another in sequence. The touchpad 91 has multiple hooks 911, 912 formed on a bottom of the touchpad 91. The base 92 has multiple hooks 921, 922 formed on a top of the base 92. Of one of the frames 93, the bottom segment 931 is pivotally connected to the hook 921 in right side of the base 92, and the top segment 933 is pivotally and slidably connected to the hook 912 in left side of the touchpad 91. In the other frame 93, the bottom segment 931 is pivotally and slidably connected to the hook 922 in left side of the base 92, and the top segment 933 is pivotally connected to the hook 911 in right side of the touchpad 91. The side segments 932 of the two frames 93 are pivotally connected to each other, and intersect each other to form an X shape.
The touch pad 91 may be touched on any location thereon, and the top segment 931 and the bottom segment 932 of the frame 93 nearer to the pressing point each respectively rotate relative to the touchpad 91 and the base 92. At the same time, the frame 93 moves the other frame 93 by the side segments 932 to move up and down simultaneously, thereby making the touchpad 91 move up and down evenly without tilting.
With reference to FIG. 16, the switch 94 corresponds to a center of the touchpad 91, such that a pressing force, which may be applied on any location of the touchpad 91, can transmit to the switch 94 effectively. However, when the pressing point is adjacent to a side of the touchpad 91, the touchpad 91 is pulled down by the top segments 933 in two opposite sides. Thus, the switch 94 in the center may function as a pivot to create leverage, thereby making the touchpad 91 deform and the two opposite sides of the touchpad 91 slightly bend downward. The deformation absorbs part of the pressing force, thereby reducing a moving distance of the touchpad 91. The pressing force must be increased to abut and actuate the switch 94. Besides, the touchpad 91 may deform and be bent, such that the user's feel of pressing is less smooth.
To overcome the shortcomings, the present invention provides an input device and lifting structure for the input device to mitigate or obviate the aforementioned problems.